I've certainly been having fun getting a great education on detailing as a Newbie from all you folks. So, let me run this by the panel of experts: I've been using Rain-X on my Subaru for years, works great functionally. I definitely like what it does in terms of sheeting off the water; it really does eliminate the need for wipers at highway speeds. But now I'm looking forward to my 325xi coming in December, and I've been boning up on washes, waxes, polymers, et al. Planning on going with the Zaino system. Will Rain-X affect the Zaino polymer? Detailking has suggested using Z2 on the windows. Anyone else use it this way? Will this have the same effect? Other suggestions? Thanks.